Atmospheric Stability

Question 1

What does adiabatic mean and what are the lapse rates?

Answer 1

Adiabatic = Air cools when it rises/expands and warms when it descends/contracts
•Does not transfer heat in or out of the parcel of air
•Air rises at either the dry adiabatic lapse rate (3°C/1000ft)
•Or saturated adiabatic lapse rate (1.5°C/1000ft)

Question 2

What does DALR, SALR and ELR mean?

Answer 2

DALR = Air not saturated
SALR = Cloud will form
Environmental lapse rate(ELR) = Air surrounding the rising air

Question 3

Explain how atmospheric stability is determined

Answer 3

Unstable if surrounding air colder than SALR and DALR Because warmer air wants to rise

Stable if surrounding air warmer than SALR and DALR

if ELR is between SALR and DALR, Conditionally unstable

Question 4

Describe the typical diurnal variation of stability

Answer 4

Linked to temperature.

Increase temperature = increase instability
•Maximum instability = mid afternoon
•Decrease temperature = increase stability (Max sunrise)

Question 5

Explain why the SALR steepens with increasing height and increasing latitude

Answer 5

Water vapour becomes cloud when it reaches dew point
•Increasing altitude = reduced water vapour due rain/cloud
•Increasing latitude = reduced water vapour
•Reduced water vapour means less latent heat released

Question 6

Check rest of stuff on notability

Answer 6

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